tModLoader My friend and I were playing Calamity and killed Cryogen, and then the sky went yellow.

[baalhawk42]

So, My friend and I were playing Calamity and recently killed Cryogen (post golem if that helps), and then the sky suddenly went yellow. My friend reported that the sky was purple on their screen. I have no clue at all what happened, here are the mods I used:

Calamity
Vitality mod
Fargo's mutant mod
Pizza Plus
Bosses as NPCs